import math

x1, y1, x2, y2 = [float(i) for i in input().split()]

distance = math.sqrt((x2 - x1) **2 + (y2 - y1) ** 2)

print(distance) import math math float(i) for i in input().split() for i in input().split() i input().split() ().split () input split for i in input().split() float(i) float i x1, y1, x2, y2 = [float(i) for i in input().split()] x1 [float(i) for i in input().split()] y1 x2 y2 distance = math.sqrt((x2 - x1) **2 + (y2 - y1) ** 2) distance math.sqrt((x2 - x1) **2 + (y2 - y1) ** 2) math.sqrt math sqrt (x2 - x1) **2 + (y2 - y1) ** 2 (x2 - x1) **2 x2 - x1 x2 x1 2 (y2 - y1) ** 2 y2 - y1 y2 y1 2 print(distance) print distance x1, y1, x2, y2 = [float(i) for i in input().split()] [float(i) for i in input().split()] x1 y1, x2, y2 = [float(i) for i in input().split()] [float(i) for i in input().split()] y1 x2, y2 = [float(i) for i in input().split()] [float(i) for i in input().split()] x2 y2 = [float(i) for i in input().split()] [float(i) for i in input().split()] y2 distance = math.sqrt((x2 - x1) **2 + (y2 - y1) ** 2) math.sqrt((x2 - x1) **2 + (y2 - y1) ** 2) distance
import math

x1, y1, x2, y2 = [float(i) for i in input().split()]

distance = math.sqrt((x2 - x1) **2 + (y2 - y1) ** 2)

print(distance)